Display apparatus

ABSTRACT

A display apparatus includes an organic light-emitting device (OLED) substrate, a color control layer; a first optical layer to which the generated light of the organic light-emitting substrate is incident and from which wavelength range light is provided to the color control layer; and a second optical layer to which the wavelength-converted light of the color control layer is incident and from which display light is provided for displaying an image The first optical layer partially transmits and partially reflects light of a first wavelength range, and reflects light of a second wavelength range and light of a third wavelength range each different from the first wavelength range. The second optical layer reflects light of the first wavelength range, and transmits each of light of the second wavelength range and light of the third wavelength range.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No.10-2017-0145378, filed on Nov. 2, 2017, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the disclosure of which is incorporatedherein in its entirety by reference.

BACKGROUND 1. Field

The present disclosure relates to display apparatuses.

2. Description of the Related Art

Quantum dots are nanometer-sized semiconductor crystals, and an energybandgap of a quantum dot may be adjusted according to the size and shapeof the quantum dot. When a semiconductor material is reduced to a sizeof nanometers like the quantum dot, unique optical characteristics maybe generated due to a quantum mechanics phenomenon. In particular,quantum dots having high light-emitting efficiency in the visible lightregion and a narrow full width at half maximum (“FWHM”) are beingresearched as a next generation display material.

Research on the application of quantum dots to displays has beenperformed largely in two directions. One is a photoluminescence (“PL”)method of exciting quantum dots by using an external light source toradiate light, and the other is an electroluminescence (“EL”) method ofexciting quantum dots by using electricity to radiate light.

Hybrid technologies of applying quantum-dot materials to organiclight-emitting device (“OLED”) type displays have drawn attention. OLEDsdo not use liquid crystal unlike liquid crystal displays (“LCDs”) andhave superior efficiency compared to the LCDs, and are advantageous inthe implementation of flexible display devices.

SUMMARY

Provided are display apparatuses having excellent performance.

Provided are display apparatuses having high light utilizationefficiency and superior color characteristics.

Provided are display apparatuses which may improve a form factor such asflexibility thereof and may be usefully applied to various fields.

Provided are display apparatuses having an organic light-emitting device(“OLED”) light source and a plurality of quantum-dot color conversionelements.

Additional features will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to an embodiment, a display apparatus includes an organiclight-emitting device (“OLED”) substrate which generates a light; acolor control layer which wavelength-converts light incident thereto; afirst optical layer to which the generated light of the organiclight-emitting device substrate is incident and from which wavelengthrange light is provided to the color control layer; and a second opticallayer to which the wavelength-converted light of the color control layeris incident and from which display light is provided for displaying animage. The first optical layer partially transmits and partiallyreflects light of a first wavelength range, and reflects light of asecond wavelength range and light of a third wavelength range eachdifferent from the first wavelength range, and the second optical layerreflects light of the first wavelength range, and transmits each oflight of the second wavelength range and light of the third wavelengthrange.

The OLED substrate may generate a blue light, and the color controllayer may include a red pixel area including a first quantum dot whichconverts the blue light incident thereto to red color light, a greenpixel area including a second quantum dot which converts the blue lightincident thereto to green color light, and a blue pixel area whichtransmits the blue light incident thereto.

The color control layer may include a red pixel area, a green pixelarea, and a blue pixel area, the first optical layer may be providedfacing each of the red pixel area, the green pixel area and the bluepixel area, and the second optical layer may face the red pixel area andthe green pixel area, except the blue pixel area.

The light of the first wavelength range may have a central wavelength ofabout 420 nanometers (nm) to about 480 nm, the light of the secondwavelength range may have a central wavelength of about 500 nm to about550 nm, and the light of the third wavelength range may have a centralwavelength of about 600 nm to about 650 nm.

The first optical layer may include a first dichroic filter whichpartially transmits and partially reflects a blue light and reflects agreen light and a red light, and the second optical layer may include asecond dichroic filter which reflects the blue light and transmits thegreen light and the red light.

The first optical layer may have a reflectance of about 30% to about 70%with respect to the light of the first wavelength range.

The first optical layer may have a transmittance of about 30% to about70% with respect to the light of the first wavelength range.

The first optical layer may have characteristics of a short passdichroic filter that transmits light of a wavelength range shorter thanthe second optical layer, and the second optical layer may havecharacteristics of a long pass dichroic filter that transmits light of awavelength range longer than the first optical layer.

At least one of the first optical layer and the second optical layer mayinclude a first material layer having a first refractive index and asecond material layer having a second refractive index which isalternately and repeatedly stacked with the first material layer, thefirst material layer may include any one of magnesium fluoride, thoriumfluoride, silicon dioxide, aluminum oxide, sodium aluminum fluoride,cryolite, and epoxy, and the second material layer may include any oneof tantalum pentoxide, niobium pentoxide, zinc sulfide, zinc selenide,hafnium dioxide, zirconium dioxide, and titanium dioxide.

The OLED substrate may include a first electrode, a second electrode,and an organic emission layer between the first and second electrodes,the first electrode, the organic emission layer and the first opticallayer may be provided in order, and the first electrode, the firstoptical layer and the organic emission layer between the first electrodeand the first optical layer may form a resonance cavity structure atwhich the generated light resonates between the first electrode and thefirst optical layer to be perpendicularly provided toward the colorcontrol layer.

The second optical layer may have an anti-glare processed emittingsurface through which the display light is provided from the secondoptical layer.

The organic light-emitting device substrate may include a plurality ofpixel areas at which the light is generated, and the display apparatusmay further include a thin film transistor layer with which the pixelareas of the organic light-emitting device substrate are controlled togenerate the light, the thin film transistor layer disposed between theorganic light-emitting device substrate and the color control layer.

According to another embodiment, a display apparatus includes an organiclight-emitting device (“OLED”) substrate including a first electrode, asecond electrode, and an organic emission layer between the first andsecond electrodes; a color control layer which wavelength-converts lightincident thereto; a first optical layer to which the generated light ofthe organic light-emitting device is incident and from which wavelengthrange light is provided to the color control layer; and a second opticallayer to which the wavelength-converted light of the color control layeris incident and from which display light is provided for displaying animage, the second optical layer having transmission characteristicsdifferent from the first optical layer and reflection characteristicsdifferent from the first optical layer. The first electrode, the organicemission layer and the first optical layer are disposed in order to forma resonance cavity structure at which the generated light resonatesbetween the first electrode and the first optical layer to beperpendicularly provided toward the color control layer.

The first optical layer may partially transmit and partially reflectlight of a first wavelength range and reflect light of a secondwavelength range and light of a third wavelength range, and the secondoptical layer may reflect light of the first wavelength range andtransmit light of the second wavelength range and light of the thirdwavelength range.

The first optical layer may partially transmit and partially reflectlight of a first wavelength range, and may have a reflectance of about30% to about 70% with respect to the light of the first wavelengthrange.

The first optical layer may have characteristics of a short passdichroic filter which transmits light of a wavelength range shorter thanthe second optical layer, and the second optical layer may havecharacteristics of a long pass dichroic filter which transmits light ofa wavelength range longer than the first optical layer.

The OLED substrate may generate a blue light, and the color controllayer may include a red pixel area including a first quantum dot whichconverts the blue light incident thereto to red color light, a greenpixel area including a second quantum dot which converts the blue lightincident thereto to green color light, and a blue pixel area whichtransmits the blue light incident thereto.

The OLED substrate may be a bottom-surface emission type device.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other features will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a cross-sectional view of a display apparatus according to anembodiment;

FIG. 2 is a cross-sectional view showing an embodiment of thecharacteristics and role of a first optical layer of FIG. 1 byemphasizing the same;

FIG. 3 is a cross-sectional view showing the characteristics and role ofa second optical layer of FIG. 1 by emphasizing the same;

FIG. 4 is a graph showing an example of relative transmission andreflection characteristics of the first optical layer that is usable ina display apparatus according to an embodiment;

FIG. 5 is a graph showing an example of relative transmission andreflection characteristics of the second optical layer that is usable ina display apparatus according to an embodiment;

FIG. 6 is a cross-sectional view of a display apparatus according toanother embodiment;

FIG. 7 is a cross-sectional view of a display apparatus according tostill another embodiment;

FIG. 8 is a cross-sectional view of a configuration of an organiclight-emitting device (“OLED”) element portion that is applicable to adisplay apparatus according to an embodiment;

FIG. 9 is a cross-sectional view showing an example of a displayapparatus adopting the OLED element portion of FIG. 8 according to anembodiment; and

FIG. 10 is a cross-sectional view of an example of a display apparatusadopting the OLED element portion of FIG. 8 according to anotherembodiment.

DETAILED DESCRIPTION

Various exemplary embodiments will now be described more fully withreference to the accompanying drawings in which exemplary embodimentsare shown.

It will be understood that when an element is referred to as beingrelated to another element such as being “connected” or “coupled” toanother element, it can be directly connected or coupled to the otherelement or intervening elements may be present. In contrast, when anelement is referred to as being related to another element such as being“directly connected” or “directly coupled” to another element, there areno intervening elements present.

It will be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of exemplary embodiments.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exemplaryembodiments. As used herein, the singular forms “a,” “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. “At least one” is not to be construed as limiting“a” or “an.” “Or” means “and/or.” As used herein the term “and/or”includes any and all combinations of one or more of the associatedlisted items. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, 20%, 10% or 5% of the stated value.

Exemplary embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of exemplaryembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, exemplary embodiments should not be construedas limited to the particular shapes of regions illustrated herein butare to include deviations in shapes that result, for example, frommanufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the figures are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to limit the scope ofexemplary embodiments.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which exemplary embodiments belong. Itwill be further understood that terms, such as those defined incommonly-used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

Reference will now be made in detail to a display apparatus according toembodiments, examples of which are illustrated in the accompanyingdrawings. In the drawings, the width and thicknesses of layers andregions are exaggerated for clarity of the specification and forconvenience of explanation. Like reference numerals refer to likeelements throughout.

FIG. 1 is a cross-sectional view of a display apparatus according to anembodiment.

Referring to FIG. 1, within the display apparatus, a display substratesuch as an organic light-emitting device (“OLED”) substrate 100 may beprovided to generate light used in displaying an image, and a colorcontrol layer 300 may be provided to adjust the color of light incidentthereto which is generated and provided from the OLED substrate 100. Afirst optical layer 200 may be provided between the OLED substrate 100and the color control layer 300, and a second optical layer 400 may beprovided on the color control layer 300 such as at a light emitting sidethereof. The color control layer 300 may be arranged between the firstoptical layer 200 and the second optical layer 400, such as in adirection in which light is emitted from the display apparatus. Aninterface may be formed between respective adjacent elements among thecolor control layer 300, the first optical layer 200 and the secondoptical layer 400.

The OLED substrate 100 may be a light source of the display apparatus,and may include a first electrode 120, a second electrode 140, and anOLED layer 130 provided therebetween. The first electrode 120 may be acathode and the second electrode 140 may be an anode, or vice versa. TheOLED layer 130 may include at least one organic emission layer.Furthermore, the OLED layer 130 may further include an electrontransport layer and a hole transport layer, and additionally, a holeinjection layer and an electron injection layer.

Along a thickness direction of the display apparatus, within the OLEDsubstrate 100, a first transparent substrate 110 may be further providedunder the first electrode 120, and a second transparent substrate 150may be further provided above the second electrode 140. Accordingly, thefirst electrode 120, the OLED layer 130, and the second electrode 140may each be provided between the first transparent substrate 110 and thesecond transparent substrate 150. The first transparent substrate 110may define an outer surface of the overall display apparatus, withoutbeing limited thereto. The second transparent substrate 150 may definean outer surface of the overall OLED substrate 100, such as a light exitsurface of the OLED substrate 100, without being limited thereto.

The first and second transparent substrates 110 and 150 may include, forexample, glass or other transparent film. The first and secondtransparent substrates 110 and 150 may be flexible. In some cases, thefirst transparent substrate 110 may be replaced by an opaque substrate.

The OLED substrate 100 as a light source of the display apparatus maybe, for example, a blue OLED substrate that generates a blue light. Inthis case, the OLED substrate 100 may be configured to generate and/oremit a blue light having a peak wavelength range of about 420 nanometers(nm) to about 500 nm or about 450 nm to about 480 nm. The organicemission layer of the OLED substrate 100 may include a blue fluorescentmaterial and/or a blue phosphor material. However, the OLED substrate100 is not limited to the blue OLED substrate, and a configurationthereof may be changed in various ways.

The color control layer 300 may include quantum dots to convert thecolor of light generated from the OLED substrate 100 into another colordifferent from the generated color. In this point, the color controllayer 300 may be referred to as a quantum-dot color converter or aquantum-dot color filter. The color control layer 300 may include afirst color control element 300A having a first quantum dot QD1 providedin plurality for red conversion and a second color control element 300Bhaving a second quantum dot QD2 provided in plurality for greenconversion. Furthermore, the color control layer 300 may further includea light-transmitting element 300C that does not include quantum dots.The light-transmitting element 300C may be a light scattering elementincluding a light scattering agent therein to scatter light incidentthereto which is provided from the OLED substrate. Thelight-transmitting element 300C may not convert a color of the lightprovided from the OLED substrate 100 and may maintain the color to beemitted from the color conversion layer 300 at the light-transmittingelement 300C.

The first color control element 300A may be a red-QD containing layer,and may convert the light generated from the OLED substrate 100 to red(R) light. The second color control element 300B may be a green-QDcontaining layer, and may convert the light generated from the OLEDsubstrate 100 to green (G) light. Accordingly, the first color controlelement 300A may be referred to as a first color converter or a firstcolor conversion element, and the second color control element 300B maybe referred to as a second color conversion element or a second colorconverter. Where blue (B) light is provided from the OLED substrate 100,the light-transmitting element 300C may transmit blue (B) light.

In an exemplary embodiment, the first and second color conversionelements may be include a combination of a resin material, certainquantum dots and a light scattering agent. The light-transmittingelement 300C may include a resin material and a light scattering agent,and exclude quantum dots. The resin material may include, for example, aphotoresist (“PR”) material. The light scattering agent may include, forexample, titanium oxide (TiO₂), etc., but the present disclosure is notlimited thereto.

The display apparatus may include a pixel provided in plurality at whichlight is generated or transmitted. The pixels may provide the lightwithin the display apparatus for displaying an image. The first colorcontrol element 300A may correspond to a red (R) pixel area (orsub-pixel area) PX1. The second color control element 300B maycorrespond to a green (G) pixel area (sub-pixel area) PX2. Thelight-transmitting element 300C may correspond to a blue (B) pixel area(sub-pixel area) PX3. One or more of these pixel areas may be providedin plurality along the light-emitting surface of the OLED substrate 100.

An RGB full color of the display apparatus may be implemented by thecolor control layer 300 including the various color pixel areasdescribed above. The arrangement sequence or arrangement method of RGBsub-pixels PX1, PX2 and PX3 are exemplary and may be changed in variousways. In an exemplary embodiment, the display apparatus and layersthereof may be disposed along a plane defined by first and seconddirections which cross each other. In FIG. 1, for example, thehorizontal direction may represent the first direction and/or the seconddirection. A thickness of the display apparatus and layers thereof maybe taken along a third direction which crosses each of the first andsecond directions. In FIG. 1, for example, the vertical direction mayrepresent the thickness direction. A light emission direction may bedefined in an upward direction along the thickness of the displayapparatus in FIG. 1, without being limited thereto.

The first quantum dots QD1 that may be included in the first colorcontrol element 300A may be red-QDs, and the second quantum dots QD2that may be included in the second color control element 300B may begreen-QDs. A quantum dot means a semiconductor particle having aspherical shape of a nanometer (nm) size or a similar shape thereof, andmay have a size (diameter) of about several nanometers to about severaltens of nanometers. The quantum dot may have a singleton structure or acore-shell structure, and for a core-shell structure, the quantum dotmay have a single-shell or multi-shell structure. In an instance, aquantum dot may be configured with a core portion (central body)including or formed of a first semiconductor, and a skin potion (shellbody) including or formed of a second semiconductor.

In exemplary embodiments, the core portion (central body) material mayinclude cadmium selenide (CdSe), cadmium telluride (CdTe), cadmiumsulfide (CdS), etc., and the skin portion (shell body) material mayinclude zinc sulfide (ZnS), etc. Furthermore, a non-cadmium seriesquantum dot (“QD”) may be used. In other words, a variety of materialsthat does not include cadmium (Cd) may be applied to the quantum dot.However, the above-described materials are exemplary, and various othermaterials may be applied to the quantum dot. In an exemplary embodiment,for example, the quantum dot may include at least one material of II-VIgroup semiconductor, III-V group semiconductor, IV-VI groupsemiconductor and IV group semiconductor material.

Since the quantum dot has a relatively very small size, a quantumconfinement effect may be obtained. When particles are very small,electrons in the particle have a discontinuous energy state by an outerwall of a particle. In this case, as the size of a space in the particledecreases, the energy state of the electrons relatively increases and anenergy band gap increases, which is referred to as the quantumconfinement effect. According to the quantum confinement effect, whenlight such as an infrared ray or a visible ray is incident on quantumdots, light having a wavelength of various ranges different from thoseof the incident light may be generated.

The wavelength of light generated from a quantum dot may be determinedbased on the size, material, or structure of a particle (quantum dot).In detail, when light of a wavelength having energy greater than theenergy band gap is incident on a quantum dot, the quantum dot may absorbenergy of the light to be excited, and may return to the ground state byemitting light of a specific wavelength different from that of theincident light. In this case, as the size of a quantum dot (or the coreportion of the quantum dot) decreases, light of a relatively shortwavelength, for example, a blue-based light or a green-based light maybe generated. As the size of a quantum dot (or the core portion of thequantum dot) increases, light of a relatively long wavelength, forexample, a red-based light may be generated. Accordingly, light ofvarious colors may be implemented depending on the size of a quantum dot(or the core portion of the quantum dot) disposed within a color controlelement.

A quantum dot particle capable of emitting a green-based light may bereferred to as a green light quantum dot particle (or green quantum dotparticle), and a quantum dot particle capable of emitting a red-basedlight may be referred to as a red light quantum dot particle (or redquantum dot particle). In an exemplary embodiment, for example, a greenlight quantum dot particle (or the core part) may be a particle having awidth (diameter) of about 2 nm to about 3 nm, and a red light quantumdot particle (or the core part) may be a particle having a width(diameter) of about 5 nm to about 6 nm. The emission wavelength of lightemitted from a color control element including a quantum dot may beadjusted not only by the size (diameter) of a quantum dot, but also bythe constituent material and/or structure thereof.

In the color control layer 300, a partition wall 350 provided inplurality may be provided respectively between the first color controlelement 300A, the second color control element 300B, and thelight-transmitting element 300C. The partition walls 350 may be alight-blocking element, such as a black matrix. The partition walls 350may define a light-emitting region and/or a pixel area of the displayapparatus, without being limited thereto. In an exemplary embodiment ofmanufacturing a display apparatus, after the partition walls 350 areformed, the first color control element 300A, the second color controlelement 300B, and the light-transmitting element 300C may berespectively formed in areas defined by the partition walls 350.

The first optical layer 200 may be provided between the OLED substrate100 and the color control layer 300, and the second optical layer 400may be provided on the color control layer 300 such as at alight-emitting side of the overall display apparatus. The first opticallayer 200 may be provided under the color control layer 300 along athickness of the display apparatus, to commonly cover all of a red pixelarea PX1, a green pixel area PX2 and a blue pixel area PX3 in a top planview of the display apparatus (e.g., viewing the display apparatus fromthe light-emitting side thereof, such; as in a direction from the secondoptical layer 400 to the first optical layer 200). The second opticallayer 400 may be provided on the color control layer 300, to commonlycover the red pixel area PX1 and the green pixel area PX2, except theblue pixel area PX3 in the top plan view.

The first optical layer 200 may selectively transmit light, so as topartially transmit and partially reflect light of a first wavelengthrange, and may reflect (e.g., totally reflect or substantially totallyreflect) light of both a second wavelength range and light of a thirdwavelength range. The first optical layer 200 has semi-transmissive andsemi-reflective characteristics with respect to the light of the firstwavelength range.

The second optical layer 400 may have different transmission andreflection characteristics from the first optical layer 200. The secondoptical layer 400 may reflect (e.g., totally reflect or substantiallytotally reflect) the light of the first wavelength range, and maytransmit both the light of the second wavelength range and the light ofthe third wavelength range.

The first optical layer 200 may have a reflectance of about 30% to about70% or about 35% to about 65% with respect to the light of the firstwavelength range. Furthermore, the first optical layer 200 may have atransmittance of about 30% to about 70% or about 35% to about 65% withrespect to the light of the first wavelength range. The first opticallayer 200 may have a reflectance of about 80% or more or about 90% ormore with respect to both the light of the second wavelength range andthe light of the third wavelength range. The second optical layer 400may have a reflectance of about 80% or more or about 90% or more withrespect to the light of the first wavelength range, and a transmittanceof about 80% or more or about 90% or more with respect to both the lightof the second wavelength range and the light of the third wavelengthrange.

In exemplary embodiments, the light of the first wavelength range maycorresponding to a wavelength range of blue light, the light of thesecond wavelength range may correspond to a wavelength range of greenlight, and the light of the third wavelength range may correspond to awavelength range of red light. In an exemplary embodiment, for example,the first wavelength range or a central wavelength thereof may be about420 nm to about 500 nm or about 420 nm to about 480 nm, the secondwavelength range or a central wavelength thereof may be about 500 nm toabout 550 nm or about 510 nm to about 540 nm, and the third wavelengthrange or a central wavelength thereof may be about 610 nm to about 760nm or about 600 nm to about 650 nm.

In a detailed example, the first optical layer 200 may be a firstdichroic filter that partially transmits and partially reflects a bluelight, and reflects both a green light and a red light. The secondoptical layer 400 may be a second dichroic filter that reflects the bluelight and transmits both the green light and the red light. In thisstate, the first optical layer 200 may have characteristics of arelatively short pass dichroic filter that transmits light of awavelength range shorter than that of the second optical layer 400. Thesecond optical layer 400 may have characteristics of a relatively longpass dichroic filter that transmits light of a wavelength range longerthan that of the first optical layer 200.

The operations of the first optical layer 200 and the second opticallayer 400 are described below in detail. The first optical layer 200 maypartially transmit and partially reflect light, for example, a bluelight, generated from the OLED substrate 100 and incident to the firstoptical layer 200. In this regard, the first optical layer 200 and thefirst electrode 120 of the OLED substrate 100 may form a resonancecavity structure CT1 with the organic emission layer at the OLED layer130 interposed therebetween. Accordingly, the light generated from theorganic emission layer may be reinforced within the OLED substrate 100by resonating between the first optical layer 200 and the firstelectrode 120 (represented by the upward and downward curved arrows inFIG. 1) and may be finally radiated upward (represented by the upwardvertical arrow in FIG. 1) to be transmitted above the first opticallayer 200 such as at a respective color control element among 300A, 300Band 300C. The upward-radiated light may exit from the first opticallayer 200 via an outer emitting surface thereof facing the color controllayer 300. Accordingly, due to the resonance cavity structure CT1,out-coupling characteristics and straightness (e.g., in a directionsubstantially perpendicular to the color control layer 300) of the lightgenerated within and emitted from the OLED substrate 100 toward thecolor control layer 300 may be much improved. The reinforced excitedlight may be incident not only at the light-transmitting element 300Crepresented by the curved upward and downward curved arrows in FIG. 1,but similarly on the quantum dots QD1 and QD2 of the color control layer300 at a respective color control element thereof, and thus colorconversion efficiency may be improved.

Furthermore, at the outer emitting surface of the first optical layer200, the first optical layer 200 may reflect light (red light and greenlight) emitted downward from the quantum dots QD1 and QD2 to be directedupward towards the second optical layer 400 (represented by the upwardcurved arrow within 300A and 300B in FIG. 1). Since the lights emittedfrom the quantum dots QD1 and QD2 have isotropy to a degree, the redlight and the green light generated by the quantum dots QD1 and QD2 maypartially travel not only in an upward direction from the color controllayer 300 toward the second optical layer 400, but also in a downwarddirection from the color control layer 300 toward the first opticallayer 200. In other words, a portion of each of the red light and thegreen light generated by the quantum dots QD1 and QD2 may traveldownward toward the first optical layer 200. At the outer emittingsurface of the first optical layer 200, the first optical layer 200 mayreflect the red light and the green light to be radiated upward andemitted from the first optical layer 200 toward the second optical layer400. Accordingly, extraction efficiency of the red light and the greenlight may be improved by the first optical layer 200.

At the outer emitting surface of the second optical layer 400, thesecond optical layer 400 which is commonly disposed at light emittingsurfaces of the first and second color control elements 300A and 300Bmay reflect the blue light of the OLED substrate 100 that is notprimarily absorbed by the quantum dots QD1 and QD2 of the first colorcontrol element 300A and the second color control element 300B to returnthe blue light to the quantum dots QD1 and QD2 (represented by the solidline arrows in FIG. 1). Since the blue light (excited light) is recycledby being reflected between the second optical layer 400 and the firstoptical layer 200, an optical path of the blue light increases so thatthe light emission efficiency of the quantum dots QD1 and QD2 may beimproved.

Furthermore, since the light emission efficiency of the quantum dots QD1and QD2 may be improved by the recycling of the light between the firstand second optical layers 200 and 400, an amount of the light scatteringagent within the color control layer 300 (e.g., the content of the lightscattering agent in 300A and 300B) such as TiO₂ used to increase theoptical path may be reduced. When the content of the light scatteringagent in the first and second color control elements 300A and 300Bdecreases, a content and/or density of the quantum dots QD1 and QD2relatively increases, and thus the efficiency of light used to displayan image may be further improved and while restricting reflection ofexternal light incident from outside the display apparatus by the lightscattering agent. Moreover, the second optical layer 400 may improvecolor purity of the color light emitted from the display apparatus todisplay an image, by reducing or effectively preventing escape of theblue light of the OLED substrate 100 to outside the display apparatusfrom light-emitting areas respectively disposed at the first and secondcolor control elements 300A and 300B.

At least one of the first optical layer 200 and the second optical layer400 may have a structure in which, for example, a first material layerhaving a first refractive index and a second material layer having asecond refractive index are alternately and repeatedly stacked withinthe respective layer. The first refractive index may be a relatively lowrefractive index or lower than the second refractive index, and thesecond refractive index may be a relatively high refractive index orhigher than the first refractive index. In exemplary embodiments, thefirst material layer described above may include, for example, any oneof magnesium fluoride, thorium fluoride, silicon dioxide, aluminumoxide, sodium aluminum fluoride, cryolite, and epoxy. The secondmaterial layer described above may include, for example, any one oftantalum pentoxide, niobium pentoxide, zinc sulfide, zinc selenide,hafnium dioxide, zirconium dioxide, and titanium dioxide.

A dichroic filter having controlled transmission characteristics andreflection characteristics may be made by repeatedly stacking twomaterial layers having different refractive indexes from each other andadjusting the thickness and the number of the layers. The dichroicfilter structure may be applied to the first optical layer 200 and/orthe second optical layer 400. At least one of the first optical layer200 and the second optical layer 400 may have a distributed Braggreflector (“DBR”) structure. Two dielectric layers having differentrefractive indexes from each other may be repeatedly stacked within anoverall filter layer structure under the condition of a thickness ofλ/4, where A is the wavelength of light, reflectance or transmittance ofa desired wavelength band may be increased. The thickness of λ/4 may bea total thickness of the overall stack of dielectric layers, withoutbeing limited thereto. However, the detailed structures and materials ofthe first and second optical layers 200 and 400 are exemplary and may bechanged in various ways.

In addition, a transparent cover layer 500 may be further provided onthe second optical layer 400. The transparent cover layer 500 may forman outer surface of the overall display apparatus, such as forming thelight-emitting surface of the overall display apparatus. The transparentcover layer 500 may include or be formed of glass or various othertransparent materials. As necessary, the transparent cover layer 500 maybe flexible.

Furthermore, a transparent layer 410 may be further provided on thecolor control layer 300 to be disposed adjacent to an end of the secondoptical layer 400. The transparent layer 410 and the second opticallayer 400 may be in a same single layer of the display apparatus. Wherethe second optical layer 400 is provided in plurality commonlycorresponding to the first and second color control elements 300A and300B, and the elements 300A, 300B and 300C are repeated within thedisplay apparatus, the transparent layer 410 may be disposed around thesecond optical layer 400 at opposing edges thereof. The transparentlayer 410 may be provided on the light-transmitting element 300C, andmay be excluded from the first and second color control elements 300Aand 300B, without being limited thereto. The transparent cover layer 500may be commonly provided on the transparent layer 410 and the secondoptical layer 400. The transparent cover layer 500 may be commonlydisposed with respect to each of the pixel areas of the displayapparatus, without being limited thereto.

FIG. 2 is a cross-sectional view showing the characteristics and role ofthe first optical layer 200 of FIG. 1 by emphasizing the same. Moreparticularly, FIG. 2 focuses on the recycling of light at the resonancecavity structure CT1 formed with the first optical layer 200, and thereflection of downward wavelength-converted light at the emittingsurface of the first optical layer 200.

Referring to FIG. 2, the first optical layer 200 may partially transmitand partially reflect the light generated from the OLED substrate 100,for example, the blue light. The first optical layer 200 and the firstelectrode 120 may form the resonance cavity structure CT1. Accordingly,due to the resonance cavity structure CT1, the out-couplingcharacteristics and straightness of the light generated from the OLEDsubstrate 100 and transmitted through the first optical layer 200 to beemitted therefrom may be much improved (represented by the upward anddownward curved arrows and vertical arrow at light-transmitting element300C in FIG. 2. Reinforced excited light may be radiated to the quantumdots QD1 and QD2, and thus color conversion efficiency may be improved.Furthermore, since the first optical layer 200 reflects the convertedlight (e.g., red light and green light at the first and second colorconversion elements 300A and 300B) radiated downward from the quantumdots QD1 and QD2 back upward toward the second optical layer 400(represented by the upward curved and vertical arrows within 300A and300B in FIG. 2), the extraction efficiency of the red light and thegreen light may be improved.

FIG. 3 is a cross-sectional view showing the characteristics and role ofthe second optical layer 400 of FIG. 1 by emphasizing the same. Moreparticularly, FIG. 3 focuses on the reflection of light not primarilyabsorbed by the quantum dots QD1 and QD2 of the first color controlelement 300A and the second color control element 300B, at a lightincident surface of the second optical layer 400.

Referring to FIG. 3, the second optical layer 400 may reflect the bluelight that has not been primarily absorbed by the quantum dots QD1 andQD2 to return the blue light to the quantum dots QD1 and QD2. Since theblue light (excited light) is recycled by being reflected between thelight incident surface of the second optical layer 400 and the lightemitting surface of the first optical layer 200 (represented by thesolid line arrows in FIG. 3), the optical path of the blue light mayincrease, and thus the light emission efficiency of the quantum dots QD1and QD2 may be improved. Furthermore, since the light emissionefficiency of the quantum dots QD1 and QD2 may be improved by therecycling of the light between the first and second optical layers 200and 400, an amount or content of the light scattering agent may bereduced in the first and second color control elements 300A and 300B,the content and/or density of the quantum dots QD1 and QD2 is relativelyincreased, and thus the efficiency of light used to display an image maybe further improved. Also, the external light reflection problem due tothe light scattering agent may be prevented. Since the second opticallayer 400 reduces or effectively prevents escape of the blue light fromto outside the display apparatus from the light-emitting areasrespectively disposed at the first and second color control elements300A and 300B, color purity of the color light emitted from the displayapparatus to display an image may be improved.

FIG. 4 is a graph showing an example of relative transmission andreflection characteristics of the first optical layer 200 that is usablein a display apparatus according to an embodiment.

Referring to FIG. 4, the first optical layer 200 may partially transmitand partially reflect the blue (B) light, and may reflect the green (G)light and the red (R) light. The first optical layer 200 may have thecharacteristics of a short pass dichroic filter that transmits light ofa relatively shorter wavelength range than that of the second opticallayer 400. In an exemplary embodiment, for example, the first opticallayer 200 may have the characteristics of a cut-off dichroic filterhaving a cut-off wavelength (e.g., the wavelength at which thetransmission decreases to 50% throughput in a short-pass filter) ofabout 450 nm. The cut-off wavelength may be, for example, about 430 nmto about 470 nm.

FIG. 5 is a graph showing an example of relative transmission andreflection characteristics of the second optical layer 400 that isusable in a display apparatus according to an embodiment.

Referring to FIG. 5, the second optical layer 400 may reflect the blue(B) light and transmit the green (G) light and the red (R) light. Thesecond optical layer 400 may have the characteristics of a long passdichroic filter that transmits light of a relatively longer wavelengthrange than that of the first optical layer 200. In an exemplaryembodiment, for example, the second optical layer 400 may have thecharacteristics of a cut-on dichroic filter having a cut-on wavelengthof about 500 nm (e.g., the wavelength at which the transmissionincreases to 50% throughput in a long-pass filter). The cut-onwavelength may be, for example, about 480 nm to about 520 nm.

According to one or more embodiment of the invention, by providing twooptical layers 200 and 400 having different transmission characteristicsand reflection characteristics respectively under and above the colorcontrol layer 300 adopting quantum dots, a display apparatus havingrelative high light efficiency and superior color characteristics may bemanufactured. As compared to an existing liquid crystal display (“LCD”),a display apparatus capable of improving a form thereof (e.g., to bedeformable) and being usefully applied to various fields of applicationmay be manufactured.

Since an LCD is operated in a method of discarding light in green/blueranges of a white light provided by a backlight to represent a red colorand discarding light in red/blue ranges to represent a green color in acolor filter, efficiency loss is generated. Also, since providing aflexible display device using the LCD backlight method is difficult,there is a limitation in improving the form factor of a display device,and the LCD backlight may be difficult to be used in various devices.Accordingly, there is a demand for a backlight-color filter methodcapable of improving light efficiency and implementing a flexibledisplay. According to one or more embodiment of the invention, a displayapparatus satisfying these requirements may be implemented.

Furthermore, since an absorption rate of quantum dots is lower than thatof an organic dye, in order to use the quantum dots as a color filterwithin a conventional display device, the optical path of the excitedlight is increased or a scattering agent such as TiO₂ is dispersed inthe quantum dot color filter. However, the scattering agent such as TiO₂may increase external light reflection. In one or more embodiment of theinvention, since the light efficiency of the quantum dots QD1 and QD2may be increased by using the two optical layers 200 and 400, use of thescattering agent may be reduced and the problems due to the scatteringagent may be restricted or effectively prevented as compared to theconventional display device.

FIG. 6 is a cross-sectional view of a display apparatus according toanother embodiment.

Referring to FIG. 6, a transparent layer 420 covering the second opticallayer 400 may be provided on the color control layer 300. Thetransparent layer 420 disposed at a side surface of the second opticallayer 420 extends to be disposed on a top surface of the second opticallayer 420. The transparent cover layer 500 may be further provided onportions of the transparent layer 420 at the side surface and at the topsurface of the second optical layer 420. In this case, the formation ofthe transparent cover layer 500 may be optional. In an exemplaryembodiment, where the transparent cover layer 500 is omitted, an uppersurface of the portions of the transparent layer 420 at the side surfaceand at the top surface of the second optical layer 420 may form alight-emitting surface of the overall display apparatus. Theconfiguration of the display apparatus in FIG. 6 except the transparentlayer 420 may be the same or similar to the configuration of FIG. 1.

FIG. 7 is a cross-sectional view of a display apparatus according tostill another embodiment.

Referring to FIG. 7, a second optical layer 400 a may have a surface S1from which light is emitted from the second optical layer 400 a, that isanti-glare processed. The anti-glare surface S1 may include, forexample, an uneven structure. The uneven structure may include aplurality of ridges and valleys which define the surface S1 of thesecond optical layer 400 a. As such, as the surface of the secondoptical layer 400 a is anti-glare processed, reflection of externallight from outside the display apparatus may be reduced or effectivelyprevented.

Although not illustrated, the surface of the transparent layer 410 maybe anti-glare processed as described above for the second optical layer400 a. In the present embodiment, the configuration of the displayapparatus in FIG. 7 except the surface of the second optical layer 400 amay be the same or similar to the configuration of FIG. 1.

FIG. 8 is a cross-sectional view of an OLED element portion that isapplicable to a display apparatus according to an embodiment. The OLEDelement portion of FIG. 8 may represent a detailed structure of the OLEDsubstrate 100 in the above-described embodiments, without being limitedthereto.

Referring to FIG. 8, a thin film transistor (“TFT”) array layer 20including a plurality of thin film transistors TFTs (not shown) asswitching devices may be provided on a transparent (base) substrate 10.Respective pixel areas of the display apparatus may be driven to displayan image using layers and devices within the TFT array layer 20. Thetransparent substrate 10 and the TFT array layer 20 together may bereferred to as one TFT array substrate. Alternatively, the TFT arraylayer 20 alone may be referred to as a TFT array substrate.

An anode electrode layer 30 including a plurality of anodes 30 a, 30 band 30 c may be provided on the TFT array layer 20. The anodes 30 a, 30b and 30 c may be elements patterned to correspond to the respectivepixel (or sub-pixel) areas of a display apparatus. Each of the anodes 30a, 30 b and 30 c may be electrically connected to respective TFTs of theTFT array layer 20. The anodes 30 a, 30 b, and 30 c may include or beformed of a transparent electrode material such as indium tin oxide(“ITO”).

An emission layer (“EML”) 50 including an organic material-basedemission material may be provided on the anode electrode layer 30. Ahole transport layer (“HTL”) 40 may be provided between the emissionlayer 50 and the anode electrode layer 30. An electron transport layer(“ETL”) 60 may be provided on the emission layer 50. A cathode electrodelayer 70 may be provided on the electron transport layer 60. Although itis not illustrated, a hole injection layer may be further providedbetween the anode electrode layer 30 and the hole transport layer 40,and an electron injection layer may be further provided between thecathode electrode layer 70 and the electron transport layer 60.

An additional material film 80 may be provided on the cathode electrodelayer 70. The additional material film 80 may be transparent or may notbe transparent. For example, the additional material film 80 may beformed of a transparent material such as glass, or an opaque material.The additional material film 80 may be a kind of a second substrate, ormay be flexible as necessary.

Although in the present embodiment the anode electrode layer 30 isillustrated to be patterned and the cathode electrode layer 70 isillustrated not to be patterned (e.g., as a solid layer), in some cases,the cathode electrode layer 70 may be patterned to be a plurality ofelectrode elements. Without patterning the anode electrode layer 30, thecathode electrode layer 70 may be patterned, or both of the anodeelectrode layer 30 and the cathode electrode layer 70 are patterned.Furthermore, the emission layer 50 located between the anode electrodelayer 30 and the cathode electrode layer 70 may have a structurepatterned in units of sub-pixels corresponding to the patterned anodeelectrode layer 30 and/or the cathode electrode layer 70. In this case,the hole transport layer 40, the emission layer 50 and the electrontransport layer 60 may be all patterned.

The OLED device of FIG. 8 may be a bottom-surface (or rear-surface)emission type device (or bottom-emission device). In other words, lightmay be emitted from the emission layer 50 toward the transparentsubstrate 10 as represented by the downward arrows in FIG. 8. Abottom-emission OLED device may not include a micro-cavity structure. Interms of manufacturing process, a bottom-emission device may be moreadvantageous than a top-emission device. In the present embodiment, thebottom-emission device may be used as an OLED element portion of adisplay. An example thereof is illustrated in FIG. 9.

FIG. 9 is a cross-sectional view showing an example of a displayapparatus adopting the OLED element portion of FIG. 8 according to anembodiment. The configuration of the first optical film 200, the colorcontrol layer 300, the second optical layer 400 and the transparentcover layer 500 of FIG. 9 may be the same or similar to theconfigurations of those element described in FIG. 1, FIGS. 6 and 7.

Referring to FIG. 9, while the OLED element portion of FIG. 8 is turnedupside down, the first optical layer 200, the color control layer 300,and the second optical layer 400 may be formed on the transparentsubstrate 10. Accordingly, the light generated from the emission layer50 may be emitted upward on the drawing through the color control layer300. In this state, the cathode electrode layer 70 and the first opticallayer 200 may form a resonance cavity structure. The TFT array layer 20may be arranged between the emission layer 50 of the OLED substrate 100and the color control layer 300.

According to another embodiment, the transparent substrate 10 may beexcluded from FIG. 9, and an example thereof is illustrated in FIG. 10.Referring to FIG. 10, the transparent substrate 10 of FIG. 9, the TFTarray layer 20 may be in a contact with the first optical layer 200.After the first optical layer 200 is first provided, by using the firstoptical layer 200 as a substrate, the TFT array layer 20 to theadditional material film 80 may be sequentially formed thereon. In thiscase, the TFT array layer 20 may be in a direct contact with the firstoptical layer 200.

FIG. 10 is a cross-sectional view showing an example of a displayapparatus adopting the OLED element portion of FIG. 8 according toanother embodiment. The configuration of the first optical film 200, thecolor control layer 300, the second optical layer 400 and thetransparent cover layer 500 of FIG. 9 may be the same or similar to theconfigurations of those element described in FIG. 1, FIGS. 6 and 7.

Alternatively to FIG. 9, after the transparent substrate 10 is removedfrom the configuration of the OLED element portion of FIG. 8 to exposethe TFT array layer 20, the first optical layer 200, the color controllayer 300 and the second optical layer 400 of the display apparatus inFIG. 10 may be formed on the TFT array layer 20.

Although FIGS. 8 to 10 illustrate a case of using one emission unitformed of the hole transport layer 40, the emission layer 50 and theelectron transport layer 60, a plurality of emission units including theabove-described three layers may be used within the OLED substrate (100in FIGS. 1, 6 and 7) of a display apparatus. In such a display apparatusincluding the plurality of emission unites, a charge generation layermay be provided respectively between the emission units. In other words,an OLED device having a tandem structure may be used.

According to one or more embodiment, a display apparatus havingrelatively high light efficiency and excellent color characteristics maybe manufactured by respectively applying the two optical layers 200 and400 having different transmission characteristics and reflectioncharacteristics from each other to upper and lower portions of the colorcontrol layer 300 having quantum dots. Furthermore, compared with aconventional LCD, a display apparatus having an improved form factor(e.g., deformable, flexible, etc.) and usefully applicable to variousapplication fields may be manufactured.

Display apparatuses according to one or more embodiment may be appliedto a variety of electronic apparatuses in which a visual display isemployed. In exemplary embodiment, for example, display apparatuses maybe usefully applied to compact electronic apparatuses such as portabledevices or wearable devices, and to relatively medium or large-sizedelectronic apparatuses.

Although there are many detailed descriptions above, they should beinterpreted to be examples of detailed embodiments, rather than to belimitations of the scope of right. In exemplary embodiments, forexample, one having ordinary skill in the art would understand that thestructures and connection relations of the OLED substrate, the colorcontrol layer, the first optical layer the second optical layer, and thedisplay apparatus including the same, which are described with referenceto FIGS. 1 to 10, may be modified in various ways. In a detailedexample, one having ordinary skill in the art would understand that thewavelength range of the light generated from the OLED substrate is notlimited to a blue color and may be variously changed, and that thestructure and characteristics of the first optical layer, the secondoptical layer and the color control layer may be variously changedaccording to the wavelength range of the light generated from the OLEDsubstrate. Furthermore, one having ordinary skill in the art wouldunderstand that a separate color filter layer may be further provided onthe second optical layer. Furthermore, one having ordinary skill in theart would understand that not only a bottom emission OLED device, butalso a front emission OLED device may be used in some cases.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features within each embodiment shouldtypically be considered as available for other similar features in otherembodiments.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. A display apparatus comprising: an organiclight-emitting device substrate which generates a light; a color controllayer which wavelength-converts light incident thereto; a first opticallayer to which the generated light of the organic light-emitting devicesubstrate is incident and from which wavelength range light is providedto the color control layer; and a second optical layer to which thewavelength-converted light of the color control layer is incident andfrom which display light is provided for displaying an image, whereinthe first optical layer partially transmits and partially reflects lightof a first wavelength range, and reflects light of a second wavelengthrange and light of a third wavelength range each different from thefirst wavelength range, and the second optical layer reflects light ofthe first wavelength range, and transmits each of light of the secondwavelength range and light of the third wavelength range.
 2. The displayapparatus of claim 1, wherein the organic light-emitting devicesubstrate generates a blue light, and the color control layer whichwavelength-converts the light incident thereto comprises: a red pixelarea comprising a first quantum dot which converts the blue lightincident thereto to red color light, a green pixel area comprising asecond quantum dot which converts the blue light incident thereto togreen color light, and a blue pixel area which transmits the blue lightincident thereto.
 3. The display apparatus of claim 1, wherein the colorcontrol layer which wavelength-converts the light incident theretocomprises a red pixel area, a green pixel area and a blue pixel area,the first optical layer from which the wavelength range light isprovided to the color control layer is disposed facing each of the redpixel area, the green pixel area and the blue pixel area of the colorcontrol layer, and the second optical layer to which thewavelength-converted light of the color control layer is incident isdisposed facing each of the red pixel area and the green pixel area ofthe color control layer and is excluded at the blue pixel area thereof.4. The display apparatus of claim 1, wherein the light of the firstwavelength range has a central wavelength of about 420 nanometers toabout 480 nanometers, the light of the second wavelength range has acentral wavelength of about 500 nanometers to about 550 nanometers, andthe light of the third wavelength range has a central wavelength ofabout 600 nanometers to about 650 nanometers.
 5. The display apparatusof claim 1, wherein the first optical layer comprises a first dichroicfilter which partially transmits and partially reflects a blue light,and reflects a green light and a red light, and the second optical layercomprises a second dichroic filter which reflects the blue light, andtransmits the green light and the red light.
 6. The display apparatus ofclaim 1, wherein the first optical layer has a reflectance of about 30%to about 70% with respect to the light of the first wavelength range. 7.The display apparatus of claim 1, wherein the first optical layer has atransmittance of about 30% to about 70% with respect to the light of thefirst wavelength range.
 8. The display apparatus of claim 1, wherein atleast one of the first optical layer and the second optical layerincludes a first material layer having a first refractive index and asecond material layer having a second refractive index which isalternately and repeatedly stacked with the first material layer, thefirst material layer comprises any one of magnesium fluoride, thoriumfluoride, silicon dioxide, aluminum oxide, sodium aluminum fluoride,cryolite and epoxy, and the second material layer comprises any one oftantalum pentoxide, niobium pentoxide, zinc sulfide, zinc selenide,hafnium dioxide, zirconium dioxide and titanium dioxide.
 9. The displayapparatus of claim 1, wherein the organic light-emitting devicesubstrate comprises a first electrode, a second electrode, and anorganic emission layer which is between the first and second electrodesand with which the light is generated, in order are disposed the firstelectrode, the organic emission layer, the second electrode and thefirst optical layer, and the first electrode, the first optical layerand the organic emission layer form a resonance cavity structure atwhich the generated light resonates between the first electrode and thefirst optical layer to be perpendicularly provided toward the colorcontrol layer.
 10. The display apparatus of claim 1, wherein the secondoptical layer comprises an anti-glare processed emitting surface throughwhich the display light is provided from the second optical layer. 11.The display apparatus of claim 1, wherein the organic light-emittingdevice substrate comprises a plurality of pixel areas at which the lightis generated, further comprising a thin film transistor layer with whichthe pixel areas of the organic light-emitting device substrate arecontrolled to generate the light, the thin film transistor layerdisposed between the organic light-emitting device substrate and thecolor control layer.
 12. A display apparatus comprising: an organiclight-emitting device substrate which generates a light, comprising afirst electrode, a second electrode, and an organic emission layerbetween the first and second electrodes; a color control layer whichwavelength-converts light incident thereto; a first optical layer towhich the generated light of the organic light-emitting device isincident and from which wavelength range light is provided to the colorcontrol layer; and a second optical layer to which thewavelength-converted light of the color control layer is incident andfrom which display light is provided for displaying an image, the secondoptical layer having transmission characteristics different from thefirst optical layer and reflection characteristics different from thefirst optical layer, wherein the first electrode, the organic emissionlayer and the first optical layer are disposed in order to form aresonance cavity structure at which the generated light resonatesbetween the first electrode and the first optical layer to beperpendicularly provided toward the color control layer.
 13. The displayapparatus of claim 12, wherein the first optical layer partiallytransmits and partially reflects light of a first wavelength range, andreflects light of a second wavelength range and light of a thirdwavelength range each different from the first wavelength range, and thesecond optical layer reflects light of the first wavelength range andtransmits each of light of the second wavelength range and light of thethird wavelength range.
 14. The display apparatus of claim 12, whereinamong the generated light of the organic light-emitting layer, the firstoptical layer partially transmits and partially reflects light of afirst wavelength range, and has a reflectance of about 30% to about 70%with respect to the light of the first wavelength range.
 15. The displayapparatus of claim 12, wherein the first optical layer hascharacteristics of a short pass dichroic filter which transmits light ofa wavelength range smaller than a wavelength range of light transmittedby the second optical layer, and the second optical layer hascharacteristics of a long pass dichroic filter which transmits light ofa wavelength range larger than a wavelength range of light transmittedby the first optical layer.
 16. The display apparatus of claim 12,wherein the organic light-emitting device substrate generates a bluelight, and the color control layer which wavelength-converts the lightincident thereto comprises: a red pixel area comprising a first quantumdot which converts the blue light incident thereto to red color light, agreen pixel area comprising a second quantum dot which converts the bluelight incident thereto to green color light, and a blue pixel area whichtransmits the blue light incident thereto.
 17. The display apparatus ofclaim 12, wherein the organic light-emitting device substrate comprisingthe organic emission layer between the first and second electrodes is abottom-surface emission type device.
 18. A method of displaying an imageby a display apparatus, the method comprising: providing an incidentlight from a light-generating member to a color control layer whichwavelength-converts light incident thereto, the providing the incidentlight comprising: providing the incident light from the light-generatingmember to a first optical layer which partially transmits and partiallyreflects light of a first wavelength range, and reflects light of asecond wavelength range and light of a third wavelength range eachdifferent from the first wavelength range, and providing the transmittedlight of the first optical layer to the color control layer whichwavelength-converts the light incident thereto; providing thewavelength-converted light from the color control layer to a secondoptical layer which reflects light of the first wavelength range, andtransmits each of light of the second wavelength range and light of thethird wavelength range; and providing the transmitted light of thesecond optical layer to outside the display apparatus to display theimage, wherein the providing of the incident light from thelight-generating member to the color control layer comprises: providingthe light-generating member comprising a first electrode, a secondelectrode, and an organic emission layer which is disposed between thefirst and second electrodes and with which the light is generated, anddisposing in order the first electrode, the organic emission layer andthe first optical layer, to form a resonance cavity structure at whichthe incident light resonates between the first electrode and the firstoptical layer to be perpendicularly emitted toward the color controllayer.